package com.slf.flow.oss.utils;

import org.apache.commons.lang3.StringUtils;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
public class FileUtils {
    public static InputStream returnBitMap(String path) {
        if (StringUtils.isBlank(path)) {
            return null;
        }
        URL url = null;
        InputStream is = null;
        try {
            url = new URL(path);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        try {
            // 利用HttpURLConnection对象,我们可以从网络中获取网页数据.
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            //设置请求方式为"GET"
            conn.setRequestMethod("GET");
//        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
            conn.setRequestProperty("User-Agent", "Mozilla/4.76");
            //超时响应时间为10秒
            conn.setConnectTimeout(10 * 1000);
            //通过输入流获取图片数据
            is = conn.getInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return is;
    }


    public static void main(String[] args) throws Exception {
        //定义一个URL对象，就是你想下载的图片的URL地址
//        URL url = new URL("https://www.unmannedsystemstechnology.com/wp-content/uploads/2022/04/Auterion-Elsight.png");
        URL url = new URL("https://wb.flk.npc.gov.cn/flfg/PDF/23c5701aad3545149a3776cde9490aa3.pdf");

        //打开连接
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        //设置请求方式为"GET"
        conn.setRequestMethod("GET");
//        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
        conn.setRequestProperty("User-Agent", "Mozilla/4.76");
        //超时响应时间为10秒
        conn.setConnectTimeout(10 * 1000);
        //通过输入流获取图片数据
        InputStream is = conn.getInputStream();
        //得到图片的二进制数据，以二进制封装得到数据，具有通用性
        byte[] data = readInputStream(is);
        //创建一个文件对象用来保存图片，默认保存当前工程根目录，起名叫Copy.jpg
        File imageFile = new File("/Users/mr.cheng/Desktop/aa.pdf");
        //创建输出流
        FileOutputStream outStream = new FileOutputStream(imageFile);
        //写入数据
        outStream.write(data);
        //关闭输出流，释放资源
        outStream.close();
    }

    public static byte[] readInputStream(InputStream inStream) throws Exception {
        ByteArrayOutputStream outStream = new ByteArrayOutputStream();
        //创建一个Buffer字符串
        byte[] buffer = new byte[6024];
        //每次读取的字符串长度，如果为-1，代表全部读取完毕
        int len;
        //使用一个输入流从buffer里把数据读取出来
        while ((len = inStream.read(buffer)) != -1) {
            //用输出流往buffer里写入数据，中间参数代表从哪个位置开始读，len代表读取的长度
            outStream.write(buffer, 0, len);
        }
        //关闭输入流
        inStream.close();
        //把outStream里的数据写入内存
        return outStream.toByteArray();
    }
}
